Essential Calculator Hacks for Math Exams

Okay so looking at our first hack here we have table mode. So for the first question we're going to have a look at we are going to be using what we call table mode. So if we go into our menu and click three we can then access table mode. From here we can type in the equation that we are given in a question for a graph that we are looking to draw. So for this one I just press alpha and that right bracket to access that x button. Typing it in as we can see there and then clicking equals we want to put in our start and end number. So the table goes from negative two to four. So negative two is our start number, four is our end number and that goes up in steps of ones. Now for most tables it typically always goes up in steps of ones if you look at that table there it goes negative two negative one zero one two three four so it goes up in ones each time. So once we've entered that we're happy that the start and end number is correct we can press equals and you'll see that we have all of our numbers here on the right hand side so we can go through we can write those in the appropriate places of course you can check any numbers that were given to you in the question and you can type those in as well. And there we go, we can go all the way down to four, and there we go, we can enter those numbers into the table. Of course, if we're then asked to plot a graph, these are our x and y coordinates, and we can draw that on the grid. But of course, not part of our sort of calculator hack here, so we're not going to actually draw the graph on the grid. So this works for any equation, whether you have a quadratic, even a linear graph, or a cubic, like the next one we're going to have a quick go at, and you could do this for a reciprocal graph as well. Let's have a look and let's do this for our cubic graph. So for this one we have 5 minus x cubed. So again we're in table mode. 5 subtract alpha bracket to get that x. And then powers you can either use your squared cubed or the empty power button. But there we go. 5 minus x cubed. We don't need a second equation so we can click past that. And for this one we do have the same starting number. So we have negative 2. That's obviously going up to 4. I could just go back actually and just put... the correct end number in even though it won't actually matter. If we go up to 4 in the table, of course, if we just read those numbers correctly. So let's put in that end number there as 2. So we want 2 as our end number for this table. Again, steps of ones. And there we go, we have our full complete table. And you can see in the second one here, next to the negative 1, we have that value of 6, which is given to us in the table. So we can just scrolling through, entering those numbers into our table. and then of course drawing the graph whenever we've got them all written down. So calculator hack number two we're going to be looking at prime factors. So we need to come out of table mode so let's go back to normal mode there and we're going to enter this number 84 into our calculator. Now once we've done that we do need to press equals that number needs to be stored in the calculator in order for this to work. Once we've done that we can click this fact button here so we need to press shift to get that, click fact and there we go we have our number and it will be given to us as a product of prime factors. So we can write that down 2 squared times 3 times 7 and of course we can use that to answer questions like these with highest common factors and lowest common multiples. So here where we have the highest common factor of 60 and 84 we can also do the product of prime factors for 60 again entering that into the calculator, shift and then using our fact button there. And now we can write that number down. So 2 squared times 3 times 5. We can now compare the prime factors. So for the highest common factor, we have a look at the factors that are within both. So here we have a 2, another 2, and a 3, which are in both. So there we go. We would just do 2 times 2 times 3. We get our highest common factor there, which is 12. For the lowest common multiple, we just have a look at whatever factors are remaining. So we already have the 2 times 2 times 3, but we also have a 5 in one of the numbers and a 7 in our other number. So we just do 2 times 2 times 3 times 5 and times the 7, and that gives us a lowest common multiple of 420. And there we go, that's using our factors button. Okay, so on to hack 3, we're going to use the time button. So this question here is looking at speed, distance and time. Now when we are looking at speed, distance and time, or whatever question when we are dealing with time, of course here if we are dealing with all three we want to write down our speed, distance and time formula. So speed is equal to distance over time. This particular question is giving us two distances and two speeds for each of those distances. It says Ollie left home at 9.30am, what time does he arrive in Sheffield? And it's given us the information for those two earlier parts of the journey. Now there's lots of different types of questions here but ultimately in this question we're trying to work out a time. So distance divided by speed will be our formula that we will use for time. So for the first part of the journey here we have a distance of 56 kilometers so we would do 56 and we're going to divide that by the speed in this question which is 70 for that part of the journey and if we click equals that comes out as 0.8. Now it's quite often that people write this down and not necessarily know how to convert this into hours and minutes. Now there are lots of different ways that you can do this. You can of course do things like multiplying by 60 if you know this very well, but in the heat of the moment you can click this button here and it's going to convert it straight into minutes for you. So that's your time button and it just allows you to convert hours into minutes with the click of the button. So Of course, there are other methods you can use for this, but that's a really nice method there just for getting those minutes straight away. Now you'll notice it's written in a bit of a strange format. So here where the zero is, that's where your hours will go. Then where the 48 is, that's where your minutes will go. And then that zero at the end is where the seconds will go if the seconds were involved in a question. But there we go. That is our first one there, 48 minutes. We can now use the second part of this question. So we have 61 as our distance divided by 48.8 as our speed. When we click equals for this one, we get 1.25 and 1.25. Again, quite a common mistake would be for somebody to write down 1 hour and 25 minutes at this point, and it's absolutely not. So just make sure you click that time button, and there we go. It converts it straight away into an hour and 15 minutes. So we had our two parts of the journey there. Of course, you could now just add those together in terms of the hours and minutes. Or what you could do is you could just get those two hourly decimals, so 0.8 and 1.25. We can add those two together. We can write that as our decimal, click our time button, and there we go. We know it's two hours and three minutes later. So if Ollie left home at 9.30, well, two hours after that would be 11.30. And then three minutes onto that would be 11.33. And there we go. Just using our time button to get the appropriate time there from those hourly decimals that we were given. Okay, so hack number four, we're looking at percentages. So for this one, we are going to look at a compound interest question. And specifically, we're going to look at the use of a multiplier. So here we are getting an additional 3.5%. Now, if we type that in, For compound interest, that means we're going up by 3.5%, which means we're going to get 103.5%. Now if you type that into your calculator, 103.5, you can actually get the multiplier that you need to use. So here, 103.5% of course is going to be our new amount after we've increased by 3.5%. Now you might know what the multiplier is for that, or how to increase by 3.5%. But if we press this percentage button here, it actually just tells us anyway. So we don't need to worry about, well, do I divide by 100 or how do I convert it? What you do do is divide by 100, but you can just use your percentage button. If you just click that percentage, it gives you the multiplier and then you don't even need to think about it. So a really nice little trick there for using your percentage button. So here we also have a 2.5% increase. So if we press 102.5%. And it gives us our multiplier there as well, so 1.025. So from there, if you are sort of happy with compound interest, you can either use the multipliers, or actually what we can do is go ahead and just use those percentages. So for this question, where we have £2,000 in a savings account, we're going up by 103.5% here, which is an additional 3.5%. Now, it says in this question... we're getting that for the first two years and then after that we're getting the 102.5% or just that extra 2.5% that'll be in an extra three years. So here if I want to increase by 3.5% I've got 103.5% Two years will be a power of two and then we can straight away go into that 102.5% and 102.5% and for this one we're going to need three years so we'll put three years in, clicking equals and that's going to give us that final amount that's going to increase it for us and that's just using the multipliers. Remember to go back into your calculator, double check you've typed everything in correctly, you don't want to make a mistake because there's a lot of buttons here that we are pressing. But there we go, that is our final amount there, £2,307.18. And we're going to round that to the nearest penny, as we are looking at money here, just cut off after that nearest penny, so 18p. And there we go, that was using the percentage button. Of course, absolutely fine, just to write down the multipliers and use it like that anyway, but a really good method here for working out percentages, you can apply this to lots of different topics, and it's definitely worth having a little play around with that. percentage button as it can save you a good bit of time in an exam. Okay so hack five we're looking at the storage button. So in this question I have picked an iterations question for us to have a look at which is a hire only topic but we are not using a hire only skill here on the calculator. So a couple of different things that I'm going to show you that you might be able to apply no matter which TO you are doing but this does work really nicely for iterations so we're going to have a look at this iterations question. So for this one here, we need to type in the cube root of 10, take away 2, multiplied by our starting number. And our starting number is 2, so here we get 1.817. Now with iterations or any topic here where you want to use the previous answer, I'm going to show you two different things in this one. What we can do is we can go back into our calculator, delete the two, and we want to put our next... or our last answer that was in the calculator. So all I need to do is use that answer button, it'll put my previous answer in, and then of course we can write down this next value as well. And for iterations it works really nicely because for the third solution that we're finding, it's now got my new answer that all that answer button will use. So all I need to do is click equals again and it will give me my third solution as well. So clicking equals, and there we go, we've got our third solution. And all I need to do is write that down. So as long as I use this answer button, iterations is really nice and quick to sort of move your way through as long as you've typed that formula in correctly. But what we can do, you don't necessarily have to use it for this topic or any topic, but it's a really nice method when we are using iterations. So I'm going to retype this formula in. And there we go. This was our first solution, 1.817. Now, what we're going to do is store this number in the calculator. So to do that, I just need to click. the store button which is just here and then click A. So that's how we're going to use these letters. So now what I can do is I can go back into my calculator. I can type in my formula again but this time I want to press my alpha button and select A. So that's going to recall that number that we just used and there we go you can see that matches our second solution. Again I'm going to store this number in the calculator. I'm going to store it this time as B though and then I'm going to type it all back in again. And this time I'm going to use that number for b. So there we go, 2 times alpha b. And there we go, we get our third answer. And again, I'd write that down, but I'm going to store that as c. And what I can do at this point, now that I've stored all of those numbers in my calculator, I can now go into the storage and I can recall those. So if I press shift and then storage, I can recall all those numbers in the calculator. And there we go, and I can compare those to the ones that we've already written down. But as you can see, it's stored all those three numbers for me, which just means it's perfect for me to now copy all of those down. And there we go, and that is using the storage button. Now, of course, if you have a question with a lot of steps or something where you just need to store numbers that you think that you might need to come back and use them again in a calculation, it's always quite handy to do that, particularly on those questions where something comes out. and it's got sort of seven, eight decimal places, and you just want to write down three of them on your working, but you want to keep it on your calculator, and you've accidentally pressed a button, and it's got rid of it, you've got to type it all back in again. It can be a real pain, particularly if you need to use that number. So a really good method, you can store those, and you can always just write down next to your numbers on the paper that it was A, B, C, or D that you were using. So you can go back into your calculator and just recall it whenever you need. But there we go, that was five calculator hacks. Now, One thing that's really important to make sure that you do is always remember to reset your calculator. So what we're going to do is just reset our calculator. So to do that on this calculator, I have to press shift and then nine for the reset. It will tell you what to do, but for me, I press three for everything. equals for yes and then I just need to press ac and that's going to reset everything and a really good technique just to make sure you have that small letter d at the top and that is for degrees and if there's anything that's sort of on your calculator screen at the top which is sort of different to what I have at the moment then it's always worth just resetting your calculator particularly if you're using a calculator that might be borrowed or it might be someone that your school's providing to you and it's been in a previous lesson before the exam and it's been also all sorts of strange settings have been put on there just grab your calculator and reset it straight away so it's in that perfect setting for your exam and nothing is going to put you off but there we go there are my five calculator hacks that you're going to need for your exam you might find all of them really helpful you might find some of them helpful you might have already known some of them but hopefully that's a nice reminder if you already knew them or hopefully you've picked up some useful information there that you can take into your exam with you. But there we go, that is the end of my five calculator hacks. Now hopefully you've got your revision under control and you're making great progress towards paper one, but if you're struggling to know where to start and need to maximise your maths in minimum time then you should sign up for my rapid revision program, Upgrade, as you can use it to build your very own personalised revision plan. Which means all you need to do is complete my revision quiz, and you'll know exactly which lessons or topics you need to work on to maximise your maths in minimum time. This is my paid programme, but you can sign up for a free trial on my website now. And if you feel like you need top-tier support direction from me, then sign up for my live, weekly, interactive lessons, which include revision-specific lessons focusing on the topics that I expect to appear in exam papers 1, 2 and 3.

Typing it in as we can see there and then clicking equals we want to put in our start and end number. So the table goes from negative two to four. So negative two is our start number, four is our end number and that goes up in steps of ones. Now for most tables it typically always goes up in steps of ones if you look at that table there it goes negative two negative one zero one two three four so it goes up in ones each time. So once we've entered that we're happy that the start and end number is correct we can press equals and you'll see that we have all of our numbers here on the right hand side so we can go through we can write those in the appropriate places of course you can check any numbers that were given to you in the question and you can type those in as well.

And there we go, we can go all the way down to four, and there we go, we can enter those numbers into the table. Of course, if we're then asked to plot a graph, these are our x and y coordinates, and we can draw that on the grid. But of course, not part of our sort of calculator hack here, so we're not going to actually draw the graph on the grid.

So this works for any equation, whether you have a quadratic, even a linear graph, or a cubic, like the next one we're going to have a quick go at, and you could do this for a reciprocal graph as well. Let's have a look and let's do this for our cubic graph. So for this one we have 5 minus x cubed. So again we're in table mode. 5 subtract alpha bracket to get that x.

And then powers you can either use your squared cubed or the empty power button. But there we go. 5 minus x cubed.

We don't need a second equation so we can click past that. And for this one we do have the same starting number. So we have negative 2. That's obviously going up to 4. I could just go back actually and just put... the correct end number in even though it won't actually matter. If we go up to 4 in the table, of course, if we just read those numbers correctly.

So let's put in that end number there as 2. So we want 2 as our end number for this table. Again, steps of ones. And there we go, we have our full complete table.

And you can see in the second one here, next to the negative 1, we have that value of 6, which is given to us in the table. So we can just scrolling through, entering those numbers into our table. and then of course drawing the graph whenever we've got them all written down.

So calculator hack number two we're going to be looking at prime factors. So we need to come out of table mode so let's go back to normal mode there and we're going to enter this number 84 into our calculator. Now once we've done that we do need to press equals that number needs to be stored in the calculator in order for this to work. Once we've done that we can click this fact button here so we need to press shift to get that, click fact and there we go we have our number and it will be given to us as a product of prime factors.

So we can write that down 2 squared times 3 times 7 and of course we can use that to answer questions like these with highest common factors and lowest common multiples. So here where we have the highest common factor of 60 and 84 we can also do the product of prime factors for 60 again entering that into the calculator, shift and then using our fact button there. And now we can write that number down.

So 2 squared times 3 times 5. We can now compare the prime factors. So for the highest common factor, we have a look at the factors that are within both. So here we have a 2, another 2, and a 3, which are in both. So there we go.

We would just do 2 times 2 times 3. We get our highest common factor there, which is 12. For the lowest common multiple, we just have a look at whatever factors are remaining. So we already have the 2 times 2 times 3, but we also have a 5 in one of the numbers and a 7 in our other number. So we just do 2 times 2 times 3 times 5 and times the 7, and that gives us a lowest common multiple of 420. And there we go, that's using our factors button. Okay, so on to hack 3, we're going to use the time button.

So this question here is looking at speed, distance and time. Now when we are looking at speed, distance and time, or whatever question when we are dealing with time, of course here if we are dealing with all three we want to write down our speed, distance and time formula. So speed is equal to distance over time.

This particular question is giving us two distances and two speeds for each of those distances. It says Ollie left home at 9.30am, what time does he arrive in Sheffield? And it's given us the information for those two earlier parts of the journey.

Now there's lots of different types of questions here but ultimately in this question we're trying to work out a time. So distance divided by speed will be our formula that we will use for time. So for the first part of the journey here we have a distance of 56 kilometers so we would do 56 and we're going to divide that by the speed in this question which is 70 for that part of the journey and if we click equals that comes out as 0.8. Now it's quite often that people write this down and not necessarily know how to convert this into hours and minutes.

Now there are lots of different ways that you can do this. You can of course do things like multiplying by 60 if you know this very well, but in the heat of the moment you can click this button here and it's going to convert it straight into minutes for you. So that's your time button and it just allows you to convert hours into minutes with the click of the button. So Of course, there are other methods you can use for this, but that's a really nice method there just for getting those minutes straight away.

Now you'll notice it's written in a bit of a strange format. So here where the zero is, that's where your hours will go. Then where the 48 is, that's where your minutes will go. And then that zero at the end is where the seconds will go if the seconds were involved in a question. But there we go.

That is our first one there, 48 minutes. We can now use the second part of this question. So we have 61 as our distance divided by 48.8 as our speed. When we click equals for this one, we get 1.25 and 1.25.

Again, quite a common mistake would be for somebody to write down 1 hour and 25 minutes at this point, and it's absolutely not. So just make sure you click that time button, and there we go. It converts it straight away into an hour and 15 minutes.

So we had our two parts of the journey there. Of course, you could now just add those together in terms of the hours and minutes. Or what you could do is you could just get those two hourly decimals, so 0.8 and 1.25. We can add those two together.

We can write that as our decimal, click our time button, and there we go. We know it's two hours and three minutes later. So if Ollie left home at 9.30, well, two hours after that would be 11.30.

And then three minutes onto that would be 11.33. And there we go. Just using our time button to get the appropriate time there from those hourly decimals that we were given.

Okay, so hack number four, we're looking at percentages. So for this one, we are going to look at a compound interest question. And specifically, we're going to look at the use of a multiplier. So here we are getting an additional 3.5%.

Now, if we type that in, For compound interest, that means we're going up by 3.5%, which means we're going to get 103.5%. Now if you type that into your calculator, 103.5, you can actually get the multiplier that you need to use. So here, 103.5% of course is going to be our new amount after we've increased by 3.5%. Now you might know what the multiplier is for that, or how to increase by 3.5%.

But if we press this percentage button here, it actually just tells us anyway. So we don't need to worry about, well, do I divide by 100 or how do I convert it? What you do do is divide by 100, but you can just use your percentage button.

If you just click that percentage, it gives you the multiplier and then you don't even need to think about it. So a really nice little trick there for using your percentage button. So here we also have a 2.5% increase. So if we press 102.5%.

And it gives us our multiplier there as well, so 1.025. So from there, if you are sort of happy with compound interest, you can either use the multipliers, or actually what we can do is go ahead and just use those percentages. So for this question, where we have £2,000 in a savings account, we're going up by 103.5% here, which is an additional 3.5%.

Now, it says in this question... we're getting that for the first two years and then after that we're getting the 102.5% or just that extra 2.5% that'll be in an extra three years. So here if I want to increase by 3.5% I've got 103.5% Two years will be a power of two and then we can straight away go into that 102.5% and 102.5% and for this one we're going to need three years so we'll put three years in, clicking equals and that's going to give us that final amount that's going to increase it for us and that's just using the multipliers.

Remember to go back into your calculator, double check you've typed everything in correctly, you don't want to make a mistake because there's a lot of buttons here that we are pressing. But there we go, that is our final amount there, £2,307.18. And we're going to round that to the nearest penny, as we are looking at money here, just cut off after that nearest penny, so 18p.

And there we go, that was using the percentage button. Of course, absolutely fine, just to write down the multipliers and use it like that anyway, but a really good method here for working out percentages, you can apply this to lots of different topics, and it's definitely worth having a little play around with that. percentage button as it can save you a good bit of time in an exam.

Okay so hack five we're looking at the storage button. So in this question I have picked an iterations question for us to have a look at which is a hire only topic but we are not using a hire only skill here on the calculator. So a couple of different things that I'm going to show you that you might be able to apply no matter which TO you are doing but this does work really nicely for iterations so we're going to have a look at this iterations question.

So for this one here, we need to type in the cube root of 10, take away 2, multiplied by our starting number. And our starting number is 2, so here we get 1.817. Now with iterations or any topic here where you want to use the previous answer, I'm going to show you two different things in this one.

What we can do is we can go back into our calculator, delete the two, and we want to put our next... or our last answer that was in the calculator. So all I need to do is use that answer button, it'll put my previous answer in, and then of course we can write down this next value as well. And for iterations it works really nicely because for the third solution that we're finding, it's now got my new answer that all that answer button will use. So all I need to do is click equals again and it will give me my third solution as well.

So clicking equals, and there we go, we've got our third solution. And all I need to do is write that down. So as long as I use this answer button, iterations is really nice and quick to sort of move your way through as long as you've typed that formula in correctly.

But what we can do, you don't necessarily have to use it for this topic or any topic, but it's a really nice method when we are using iterations. So I'm going to retype this formula in. And there we go. This was our first solution, 1.817.

Now, what we're going to do is store this number in the calculator. So to do that, I just need to click. the store button which is just here and then click A.

So that's how we're going to use these letters. So now what I can do is I can go back into my calculator. I can type in my formula again but this time I want to press my alpha button and select A.

So that's going to recall that number that we just used and there we go you can see that matches our second solution. Again I'm going to store this number in the calculator. I'm going to store it this time as B though and then I'm going to type it all back in again. And this time I'm going to use that number for b. So there we go, 2 times alpha b.

And there we go, we get our third answer. And again, I'd write that down, but I'm going to store that as c. And what I can do at this point, now that I've stored all of those numbers in my calculator, I can now go into the storage and I can recall those.

So if I press shift and then storage, I can recall all those numbers in the calculator. And there we go, and I can compare those to the ones that we've already written down. But as you can see, it's stored all those three numbers for me, which just means it's perfect for me to now copy all of those down.

And there we go, and that is using the storage button. Now, of course, if you have a question with a lot of steps or something where you just need to store numbers that you think that you might need to come back and use them again in a calculation, it's always quite handy to do that, particularly on those questions where something comes out. and it's got sort of seven, eight decimal places, and you just want to write down three of them on your working, but you want to keep it on your calculator, and you've accidentally pressed a button, and it's got rid of it, you've got to type it all back in again. It can be a real pain, particularly if you need to use that number. So a really good method, you can store those, and you can always just write down next to your numbers on the paper that it was A, B, C, or D that you were using.

So you can go back into your calculator and just recall it whenever you need. But there we go, that was five calculator hacks. Now, One thing that's really important to make sure that you do is always remember to reset your calculator.

So what we're going to do is just reset our calculator. So to do that on this calculator, I have to press shift and then nine for the reset. It will tell you what to do, but for me, I press three for everything. equals for yes and then I just need to press ac and that's going to reset everything and a really good technique just to make sure you have that small letter d at the top and that is for degrees and if there's anything that's sort of on your calculator screen at the top which is sort of different to what I have at the moment then it's always worth just resetting your calculator particularly if you're using a calculator that might be borrowed or it might be someone that your school's providing to you and it's been in a previous lesson before the exam and it's been also all sorts of strange settings have been put on there just grab your calculator and reset it straight away so it's in that perfect setting for your exam and nothing is going to put you off but there we go there are my five calculator hacks that you're going to need for your exam you might find all of them really helpful you might find some of them helpful you might have already known some of them but hopefully that's a nice reminder if you already knew them or hopefully you've picked up some useful information there that you can take into your exam with you. But there we go, that is the end of my five calculator hacks.

Now hopefully you've got your revision under control and you're making great progress towards paper one, but if you're struggling to know where to start and need to maximise your maths in minimum time then you should sign up for my rapid revision program, Upgrade, as you can use it to build your very own personalised revision plan. Which means all you need to do is complete my revision quiz, and you'll know exactly which lessons or topics you need to work on to maximise your maths in minimum time. This is my paid programme, but you can sign up for a free trial on my website now.

And if you feel like you need top-tier support direction from me, then sign up for my live, weekly, interactive lessons, which include revision-specific lessons focusing on the topics that I expect to appear in exam papers 1, 2 and 3.

Transcript for:Essential Calculator Hacks for Math Exams

Transcript for:
Essential Calculator Hacks for Math Exams